Microcirculation of the spleen: and open or closed circulation?

By injecting plastic microspheres of a specific size (3 to 4 micrometers) into the circulation and following their movement and distribution in the spleen, it was revealed how blood travels from the arterial capillaries to the venous sinuses. This method demonstrated that both open and closed circulation exist in the spleen and that about 90 percent of the blood takes the open route of circulation in the normal unanesthetized rabbit.